silver nitrate

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun A poisonous colorless crystalline compound, AgNO₃, that becomes grayish black when exposed to light in the presence of organic matter and is used in manufacturing photographic film, silvering mirrors, dyeing hair, plating silver, and in medicine as a cautery and antiseptic.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun inorganic chemistry The silver salt of nitric acid, AgNO3; it is sensitive to light and is used in the preparation of silver halides for photography; it is used in laboratories as a reagent to test for chloride

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a nitrate used in making photographic emulsions; also used in medicine as a cautery and as a topical antibacterial agent